完形填空。从A、B、C、D四个选项中选取最佳答案。

    Bill is my friend. He has a happy 1. His father works 2 a hospital (医院) in Beijing. He usually  3 two eggs and a glass of milk 4 breakfast and then goes to work by car. His mother is an English 5 in our school. For breakfast, She usually eats some 6. Her English class is very  7, So we all love her. Bill is also my classmate. He eats a hamburger and two bananas for breakfast. He likes ice-cream very much. 8 his mother doesn't want him to eat it. She says it is not 9. And he can be very 10 if(如果 ) he eats a lot(很多).

高铁酸钾（K₂FeO₄）是一种新型的自来水处理剂，它的性质和作用是(    )

电子计算机减轻了人脑的智力劳动，它可以进行计算、判断和推理，还可以存储巨量信息、高效率地处理这些信息．因此，人们又把它叫做电脑．如果说计算机实现了人脑的延伸，那么通信系统便是社会的神经．计算机与通信的结合将成为21世纪信息社会的基础．通过各种信息源了解目前信息技术的发展情况和对未来的展望，写出一篇科学作文，畅想50年的我们在信息化社会中的生活．

材料：在一个寒冷的冬夜，一位纽约的商人看到一个衣衫褴褛的铅笔推销员，顿生怜悯之心，他把一元钱放进推销员怀中就走开了。但是他忽然觉得这样做有些不妥，就连忙返回从推销员那里取回两支铅笔，并抱歉的说：“我忘记拿铅笔了……”

材料中这位商人的作法反映了什么问题？

下面属于生态系统的是（     ）